Adapters designed for mounting a small IC memory device are known (refer to Patent Documents 1 and 2). The adapter of Patent Document 1 has the same external dimensions as an ATM card, a credit card, or other commonly used internationally standardized cards (hereinafter referred to as “a standard card”). The adapter has a recess for fitting/mounting a small IC memory device in a designated location. Projections for engaging and holding the small IC memory device is formed on the inner edge of the recess in a circular manner. The IC memory device to be mounted comprises a memory main body shaped as a polygon with five corners obtained by cutting off a corner of a tetragon, an IC module embedded in the memory main body, input/output contact terminals disposed on a surface of the memory main body, and the like. Its surface area is slightly more than 13% of the surface area of the adapter main body. The standard card is specified in JISX6301.
In principle, the same basic configuration is adopted in the adapter of Patent Document 2. However, this configuration is different in that a storage recess for loading a small memory device is open on the top surface and peripheral side surface of the memory main body, and the memory device is insertably mounted in the storage recess from the side of the lateral opening. The total thickness of the adapter is therefore considerable when the memory device is mounted in the adapter.
Patent Document 1: Japanese Patent Laid-open Publication No. 10-272872 (Paragraph 0011, FIG. 1)
Patent Document 2: Japanese Patent Laid-open Publication No. 2002-190004 (Paragraph 0017, FIG. 1)